BackgroundThe 2017 IDSA C. difficile guidelines recommend the use of nucleic acid amplification testing alone for detection of HO-CDI if appropriate stool specimens are collected (e.g., patients not receiving laxatives and ≥3 unformed stools in 24 hours). The potential role of ID specialists in enforcing appropriate C. difficile testing is unclear.MethodsAt a single academic hospital, we performed a pilot study of an ID specialist-led approval process for C. difficile testing. During the baseline period (January 2016 and November 2017), HO-CDI testing appropriateness was enforced using a computerized decision support tool that discouraged inappropriate testing based on detected laxative use and stool frequency criteria; however, clinicians frequently ignored the computer alerts. During the intervention period (December 2017 and March 2018), all HO-CDI testing on hospital day 4 or later triggered a computer alert requesting mandatory testing approval by an ID specialist. Approvals were provided via telephone consultation 7 days a week between 8 a.m. and 5 p.m. (in both periods, CDI testing was not performed overnight). We analyzed differences HO-CDI testing and infection rates (defined by CDC’s LabID event) per 10,000 patient days using Poisson models. We also analyzed the number of approval pager calls, rates of C. difficile testing approval, and time burden.ResultsTwo infectious diseases specialists (M.Y.L.; J.S.) primarily answered C. difficile pager approval requests; the remainder of approvals were provided by ID specialists already consulted on the patients. During the intervention period, ordering providers made 159 calls to the approval pager; 119 (75%) received approval. HO-CDI testing and infection rates declined between the baseline and intervention periods (figure). There was a mean of 1.3 pager approval requests per day (range, 0–4) with an average of 3 minutes of time spent per request. ConclusionAn ID specialist-led C. difficile testing approval process was feasible and associated with a significant decrease in HO-CDI testing and infection rates, due to enforcement of appropriate testing. ID specialists can provide a key role in enforcing appropriate C. difficile testing, but more experience is needed with respect to sustainability.Disclosures M. Y. Lin, Stryker (Sage Products): Research support in the form of contributed product, Research support. OpGen, Inc: Research support in the form of contributed products, Research support. CareFusion Foundation (now BD): Grant Investigator, Research grant.